1. Field of the Invention
The invention relates generally to devices for treating surfaces of wafer-shaped articles, such as semiconductor wafers. The invention also relates to gripping pins that secure a wafer-shaped article within such devices.
2. Description of Related Art
Semiconductor wafers are subjected to various surface treatment processes such as etching, cleaning, polishing and material deposition. To accommodate such processes, a single wafer may be supported in relation to one or more treatment fluid nozzles by a chuck associated with a rotatable carrier, as is described for example in U.S. Pat. Nos. 4,903,717 and 5,513,668.
Alternatively, a chuck in the form of a ring rotor adapted to support a wafer may be located within a closed process chamber and driven without physical contact through an active magnetic bearing, as is described for example in International Publication No. WO 2007/101764 and U.S. Pat. No. 6,485,531.
Certain of the processes to which semiconductor wafers are subjected involve very aggressive chemicals applied at elevated temperatures, in which case the components of the chuck must be able to withstand those extreme process conditions. For example, certain processes utilize highly concentrated sulfuric acid at temperatures that can reach 250° C. or more, which results in a temperature increase of the wafer as well.
However, the chuck pins conventionally used to hold the wafer on the chuck, which are typically made of a chemically inert plastic such as polyetheretherketone (PEEK), cannot withstand these extreme high temperatures. If on the other hand the pins are made of a refractory material such as ceramic or quartz, the pins have insufficient mechanical strength due to the comparatively brittle nature of such materials.